A module is a self-contained component within a larger system, designed to perform specific functions while interacting with other modules through defined interfaces. In software, modules allow complex systems to be built from manageable pieces that can be developed, tested, and updated independently. Municipal software systems often use modular architecture, with separate modules for functions like property assessment, utility billing, permit management, and financial reporting. Modular design allows municipalities to customize systems, add features, and replace outdated components without rebuilding entire systems. Understanding modular architecture helps when evaluating software purchases or planning system integrations.